The effects of halothane, a volatile anesthetic, on membrane-protein interactions will be studied. Although volatile anesthetics are known to change the fluidity of membrane lipids, there are few data about effects of anesthetics on membrane proteins. The effects of halothane concentration on the activity of enzymes bound to mitochondrial and synaptic membranes will be studied. The effect of halothane concentration on the extraction of proteins from brain and liver mitochondria and from synaptosomes will be investigated. These studies will extend preliminary work by the principal who showed that halothane extracts certain proteins from beef heart mitochondria. The effect of halothane concentration on submitochondrial localization of certain enzymes and other proteins will be studied. Aspartate aminotransferase and maltate dehydrogenase have been shown to move reversibly from the inner membrane-matrix to the intermembranal fluid compartment of mitochondria. Preliminary work by the principal investigator has shown that the same enzymes are extracted from mitochondria equilibrated with high concentrations of halothane vapor. The proposed studies will increase our knowledge about the biochemical mode of action of anesthetic drugs. These data on chemical aspects of neurologic function could contribute to the design of drugs with more specific actions and fewer side effects.